Filter for liquids and gases



Aug. 2, lsa.

M. TlscHr-:Rv

FILTER FOR LIQUIDS AND GASES Filed Mach 3. 1930 Patented Aug. 2, 1932UNITED STATES ramasse)A PATENT OFFICE Application led ltarch 3, 1930,SerialNo. 482,951, and in Germany Hatch 2, 1929.

maximum difference in pressure between the liltered and unfilteredstuiiis exceeded, slit like openings are formed in the lter through which anequalization of pressure takes place at once, the slits at the same timealso operating as lilters. To thisI end ilter cells are piled up andheld together by means of a suitably disposed compression spring in suchmanner that they are free to move apart, if a certain degree ofdifference in pressure 0 is exceeded.

- whichthe outer wall The drawing shows a preferred forni of the objectof the invention.

-Fig. 1 represents 'a longitudinal section; Fig. 2 is across' section ofthe new filter. b is a circular seat in the casin a, u n ortion d o therst of the circular disk li e filter cells c rests. In likemanner thesecond cell is restin upon the lowermos't of the cells, the thir .upon

the second and so on. Upon the top cell' the cover f rests. Acompression spring e beairing upon the inside o fcasin lid Z presses thecover against the outer wa portion `o f I the top ltercell c. In thisway the spring also holdsfall the other cells together andv presses thebottom cell uponvthe seat b. Casing ribs g keep the cells in centralposition.

The upper part of cover f forms a balanc ing steppiston i with packingc, which piston slides in the casing /id Z shaped. as a guiding cylinderfor this purpose. In order to prevent the spring pushing the cover foutside the guiding cylinder if lid Lis taken oil", a stud bolt fn. isfastened to the bottom of lid Z so that coverf will rest upon the studvm of bolt n, if lid Z is taken oil'. y When in working order, there is acertain amount of play between stud m of bolt n and the stud rest partof the cover f, in order to allow the spliiing to press the coveragainst the top ce Each filter cell c consistsof a main body g, overwhich suitable ltering fabric v is strained and, united to the main bodyby ribs, anouter wall portion d. y

The resilient means adapted to pressthe lid separating the filteredsubstance from the uniltered part of the substance against the vupperfiltering cell act with a force given by the ratio of the diameter ofthe step piston connected with said lid to the diameter of said lid.

y The liquid or gaseous stuff to be filtered passes through the filteras follows. y

The liquid or gas enters the casing 'at o, flowin through circularchannels p, thus distributmg itself in parallel upon all the filtercells. The outer wall portion d of each cell is slightly higher than theilter body g, consequently the liquid or gas may freely enter anddistribute itself in the space between the several Acells upon thefabric stretched over the filter bodiesand, penetrating the lterefabricenters the interior of the bodies q. Thence the now filtered liquid orgas Hows through bores sjinto the casing a andeventually is dischargedthrough outlet t. Y

If the desirable maximal difference in pressure between filtered stuffvand raw stuff is exceeded, excess pressure of the raw stuff will liftcover f and a-narrow slit like opening will form between seat surfacela. and, circular seatd of the top cell c, some of the liquid or gaspasses lnto' thecasing a and pressure is thus at once equalized. As thewidth of this slit is only very minute, approximately the same filtereffect is obtained as with the filter fabric. The construction ofthefilter according to the nvention admits the choice of cells of thelargest diameter, thereby ensuring any depsired Width of filter slits.

Similar action takes place between the seats of any pair of cells ifthrough clogging nlp of one of them resistance in the circular c annelsp rises inadmissibly high.

Claims:

i 1. In a filter for liquids or gases, in coming. cells, each cellconsisting of a ring shaped body and an outer ring shaped wall thus'forming a circular channel, said channels communicating with spacesbetween the cells and a section of said casing having an inlet, filterfabric stretched over both ends of each of said ring shaped cell bodiesenclosing a space communicating by bores in the wall of said filterbodies with another division of the casing having an outlet, a pistonshaped lid on' top of said series of cells and a compression springwithin said lid adapted to press said lid and series of cells against aseat provided in the lower portion of said casing.

2. In a filter for liquids or gases, in combination a casing havingv asection provided with an inlet and asection provided with an outlet anda cylindrical cover, a filtering member within said casing comprising aseries of superposed disk like filter cells and a step piston shaped lidon top of said cells, partially encompassed by said cylindrical cover,said lid adapted to ascend'within said cover, if the pressure prevailingin the space between said cells exceeds the pressure prevailing insideanyone of said series of cells by a cert-ain predetermined amount,thereby establishing direct communication with the division of. saidcasing having an outlet, and means for limiting said ascending strainedover said bodies, outer walls and hollow ribs connecting said walls withsaid bodies, said main bodies and said outer walls forming channelssurrounding said main bodies for the purpose Otleading the unfilteredsubstance into the filter, a lid separating the filtered substance fromthe unfiltered part of the substance, a casing, said casing and saidouter Walls forming channels for the assage of said filtered substanceleaving the rst-mentioned channels by means of said hollow ribs.

6. In a filter for liquids or gases, in combination, a filtering membercomprising a-plurality of superposed filtering cells, a casing, a lidseparating the filtered substance from the unfiltered part of thesubstance and resilient means adapted to press said lid against theupper one of said filtering cells, said lid beingautomatically raised ata certain excess of pressure and forming an outlet for said unfilteredsubstance, said outlet being adapted to act as a filter.

In testimony whereof I have afiixed my signature.

MAX TISCHER.

motion of the lid to a degree compatible with 'l proper filtering.

3. In a. filter for liquids or gases, in combination a casing having asection provided with an inlet and a section provided with an outlet, afiltering member within said casing comprising a series of superposeddisk like filter cells, each of said cells adapted to leave its seat ifpressure prevailing' in the space below the cell exceeds the pressurewithin the cell by a .certain predetermined amount,

i thereby establishing direct communication with the division of saidcasing having an outlet, and means for limiting said motion to a degreecompatible with proper filtering.

4. In a filter for liquids or gases, in combination, a filtering membercomprising a plurality of superposed filtering cells, a casing, a lidseparating the ltered substance from the unfiltered part of thesubstance, a step piston connected with said lid and resilient meansadapted to press said lid against the upper one of said filtering cellsand to raise said lid at a certain pressure, thereby forming an outletfor said unfiltered substance, the effective lifting force being afunction of the ratio of the diameter of said piston to the diameter ofsaid lid.

5. Ina filter for liquids or gases, in combination, a filtering membercomprising a plurality of superposed ltering cells, said filteringYcells comprising main bodies, fabrics

